The invention relates to a distance adjusting device in a carding machine which has a traveling flats assembly composed of a plurality of clothed flat bars, an endless drive element, such as a flexible belt and flexible slide guides on which opposite ends on the flat bars glide. The slide guides are of outwardly convex configuration and are supported on a likewise outwardly convex supporting element forming part of the machine frame.
In practice the flat bars glide on arcuate, strip-like bars, termed as flexible bends which are arranged approximately concentrically to the carding cylinder and are secured to side plates of the machine frame in such a manner that they may be adjusted in their position by means of screw-like setting spindles. Since wear or regrinding of the clothing causes a reduction in the radius of the circle circumscribable about the points of the cylinder clothing, the flexible bends, as they approach the carding cylinder, have to be able to yield to adapt their curvature to the reduced cylinder radius. The same applies to the compensation of manufacturing tolerances. For this purpose, the flexible bends are in most cases cast from a special alloy which has a substantial elasticity and may yield to assume the required shape. An adjustment will effect a shift of approximately between 0.2 and 4 mm of the glide surface. It is a disadvantage of such a conventional arrangement that undesired bends may occur during the various radial adjustments. Further, the geometry of the flexible bend depends from the number of the setting spindles, that is, the accuracy and uniformity of the distance between the flat bar clothing and the cylinder clothing is not uniform as viewed over the entire arc. It is a further drawback that manufacturing and assembly costs are very high; a manufacture and finishing of individual components are required. The flexible bend tends to be twisted because of its own insubstantial stiffness. The complex setting process by means of the setting spindles to obtain a uniform carding gap in the circumferential direction at the assembly start or for a new setting during operation is also a disadvantage.
For improving the sliding properties of the flat bars to thus eliminate the need of a lubrication of the cast surface by a graphite block, it is known to provide a strip-like plastic slide guide in a longitudinal groove provided in the flexible bend. Such plastic slide guide on which the flat bars glide, projects slightly beyond the flexible bend and is concentric therewith. The flexible bend constitutes the support member for the slide guide.